Lymph nodes are small, bean-shaped glands that play a crucial role in the immune system. They filter lymphatic fluid, which helps rid the body of germs and remove waste products.

The body contains hundreds of lymph nodes. They form clusters around the body and are particularly prominent in areas such as the neck, armpit and groin and behind the ears.

The body’s cells and tissues dispose of waste products in lymphatic fluid, which lymph nodes then filter. During this process, they catch bacteria and viruses that could harm the rest of the body.

Lymph nodes are an essential part of the body’s immune system. Due to their function, they come into contact with toxins, which can cause them to swell. Although swollen lymph nodes are common, they may occasionally indicate lymph node cancer, or lymphoma.

Keep on reading to learn more about lymph nodes and their function within the immune system.

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Lymph nodes are part of the lymphatic system, which is a complex network of nodes and vessels.

In certain areas of the body, such as the neck, armpit, and groin, lymph nodes sit close to the skin. This means a person may feel them swell when an infection develops.

Lymph nodes are also present in the stomach and between the lungs. However, there are no lymph nodes in the brain or spinal cord.

The name of a lymph node depends on its location in the body.

Name of lymph nodeLocation
cervicalin the neck
axillaryin the armpit
inguinalin the groin

Lymph nodes form clusters throughout the body. Their main function is to filter out potentially harmful substances.

All tissues and cells in the body excrete lymphatic fluid, or lymph, in order to eliminate waste products. The lymph then travels through vessels in the lymphatic system and passes through lymph nodes for filtering.

Lymph nodes contain lymphocytes. These are a type of white blood cells that help destroy pathogens, such as bacteria, viruses, and fungi. When lymph nodes detect a pathogen in the lymph, they produce more lymphocytes, which causes them to swell.

Upon encountering bacteria or damaged cells, lymph nodes destroy them and turn them into a waste product.

When the lymph reenters the bloodstream, waste products travel to the kidneys and liver. The body then excretes waste products in the urine and feces.

Learn more about how the lymphatic system works here.

Swollen lymph nodes do not always indicate cancer. Below, we list some of many conditions that can cause lymph node swelling.

Lymphadenitis

Lymphadenitis occurs when bacteria, viruses, or fungi in the lymph infect lymph nodes. When this happens, lymph nodes swell and are painful to the touch.

If multiple clusters of nodes become infected, a person may feel pain and swelling in both their neck and groin.

The most common type of lymphadenitis is localized lymphadenitis. This means the condition only affects a few nodes. If the infection occurs in several node clusters, a doctor will likely diagnose generalized lymphadenitis.

The condition usually results from an infection elsewhere in the body.

Symptoms

Symptoms of lymphadenitis include:

  • sore, swollen nodes
  • soft or matted nodes
  • skin streaking around the nodes
  • abscesses around the nodes
  • fluid seeping from the skin

Treatment

Lymphadenitis treatments include:

The type of treatment necessary will depend on a variety of factors, such as the severity of the disease and a person’s underlying conditions and allergies. A doctor will help a person choose the most suitable treatment based on these factors.

Learn more about swollen lymph nodes in the neck here.

Viral or bacterial throat infections

Swollen lymph nodes in the neck may be due to a viral or bacterial throat infection, such as strep throat.

Viral infections

Viral throat infections, such as colds, can present with swollen lymph nodes, a runny nose, and pinkeye.

These infections usually resolve on their own. However, a person can take over-the-counter pain relievers to alleviate pain they may experience when swallowing.

Strep throat

Strep throat is a bacterial infection that develops in the throat and tonsils due to group A streptococcus. People may contract strep throat if they come into contact with droplets containing the strep bacteria.

A person with strep throat may experience swollen lymph nodes on the neck, a sore throat, a fever, and red spots on the roof of the mouth.

Doctors treat strep throat with antibiotics.

Impetigo

Impetigo is an infection that develops due to group A streptococcus and may cause lymph nodes in the armpits and groin to swell.

A person can contract impetigo when the bacteria enter the body through a break in the skin. This can happen through sharing a towel, razor, or yoga mat.

Symptoms

Symptoms of impetigo include:

  • itchy spots or sores around the nose or mouth that occur with change in skin color
  • swollen lymph nodes
  • painful sores
  • blisters

Treatment

If a person has impetigo, they should seek medical attention to address their symptoms and prevent the condition from spreading to others.

Treatment will usually involve antibiotics.

Ringworm

Ringworm, or jock itch, is a fungal infection that can affect many areas of the body. If the fungus develops in the groin, a person may experience lymph node swelling in that area.

Typically, ringworm starts as a fungal lesion. The fungus often transmits when people share towels or razors.

Ringworm thrives in moist environments, and therefore a person should take care to dry thoroughly after a wash and try not to stay in damp clothes.

Symptoms

Common ringworm symptoms include:

  • a patchy rash with a ring-like appearance and clear borders
  • itchiness
  • stinging
  • flaky skin

Treatment

A doctor will prescribe an antifungal treatment to address ringworm.

The best way to prevent ringworm is to wear breathable fabrics, avoid sharing towels and razors, and dry thoroughly after bathing.

Learn more about swollen lymph nodes in the groin here.

Lymphoma is a type of cancer that affects the lymphatic system. The two main types of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma.

Hodgkin lymphoma occurs when cancer cells spread from one cluster of lymph nodes to another. By contrast, in non-Hodgkin lymphoma, there is no order in how cancer cells spread throughout the lymphatic system.

Symptoms

Typical symptoms of lymphoma include:

These are also common symptoms of viral infections, which can make lymphoma hard to diagnose. However, in people with lymphoma, symptoms tend to persist for longer periods of time.

It is of note that these symptoms do not clearly indicate cancer. If a person experiences any of these, they should contact a doctor to identify the cause of their symptoms.

Treatment

Treatment options for lymphoma include:

  • CAR T cell therapy: This is a type of immunotherapy that uses a person’s own immune system to attack cancer cells.
  • Chemotherapy: This therapy uses medication to destroy cancer cells.
  • Radiation therapy: This treatment uses high energy beams to destroy cancer cells and shrink tumors.
  • Stem cell transplant: A person receives stem cells from a donor. After they undergo high doses of chemotherapy, which destroys cancer cells and unhealthy blood cells, doctors implant stem cells, which start to produce new, healthy blood cells.

A person should contact a healthcare professional if they are experiencing persistent swelling of lymph nodes.

Swelling usually indicates an infection, and therefore a person should not immediately worry about lymphoma.

After reaching a diagnosis, a doctor will recommend the appropriate course of treatment.

Lymph nodes are a part of the lymphatic system. They filter lymph, which contains pathogens and damaged cells, and send the dead cells to the kidneys and liver.

Lymph node swelling usually results from an infection. In rare cases, however, it may be due to lymphoma.

If a person is concerned about swelling and other symptoms they have, they should contact a doctor.